Bumgarner pitched four-hit ball for four innings and struck out four in the Giants' 2-1 win over the Texas Rangers on Monday.
"It went pretty good," said Bumgarner, who went 16-11 with a 3.37 ERA last year. "I was happy with it. I said before, each time is a step in the right direction and each time has been a little bit better."
Bumgarner, who had not thrown more than two innings in three prior starts, walked Lance Berkman in the first and gave up a double to Mitch Moreland in the second before retiring the final eight batters he faced.
The only two Texas starters absent were shortstop Elvis Andrus, who just returned from Puerto Rico where he played for Venezuela in the World Baseball Classic, and right fielder Nelson Cruz, who remains with the Dominican Republic's WBC team.
"It's getting to the time now, the end of spring, when want to get more game ready instead of just working on stuff," Bumgarner said. "You want know you're able to get guys out heading into the season."
Bumgarner's outing was far less eventful than Texas starter Yu Darvish's third start.
Darvish retired six of the first seven batters he faced but struggled a bit in the third. The right-hander allowed infield singles to Kensuke Tanaka and Tony Abreu before Hunter Pence laced a hard double into the left-field corner to give San Francisco a 1-0 lead.
It was the first run Darvish had allowed this spring.
"For two innings he had a snap-dragon slider and a lot of pop on his fastball," said Rangers manager Ron Washington. "He just threw a lot of pitches in the third inning and got his pitch count up."
"I've been trying new things," said Darvish, who allowed five hits and struck out five in 3 2/3 innings. "The hit to Pence and the hit to right, those are pitches I don't normally try during the season but I wanted to try new things and they got hit off me. But it was good to try new things."
Darvish said he's also experimented with a split-finger fastball this spring. Such experimentation comes as a result of being more comfortable with his place in Rangers camp.
"Compared to last year I think I'm enjoying this a lot more," Darvish said. "Last year I pressured myself to get outs. This year, I'm trying new things and enjoying the atmosphere a lot more."
"(Nathan) got the ball down after that," Washington said. "Those two pitches were up. He certainly knew what he had to do to get outs, and that was get the ball down."
San Francisco will play host to Japan in a scrimmage Thursday at 1 p.m. at Scottsdale Stadium. . The Giants lead the NL with 12 triples in 16 games. San Francisco led the majors with 57 triples, the first time the Giants topped that category since 1973. . Rangers SS Jurickson Profar told the Dallas Morning News he hopes to join the Netherlands' WBC squad before the second round of games begin. . Giants RHP Tim Lincecum, sidelined his past two starts because of a blister on the middle finger of right hand, will return to action Tuesday night against San Diego. . Rangers 3B Adrian Beltre, 4 for 16 this spring after returning from a strained right calf, said Monday he would not play for the Dominican Republic in the second round of the WBC. . Texas LHP Matt Harrison, scratched from his start Saturday with an inflamed toe on his left foot, will throw two innings in a "B" game Tuesday.